[Python-Dev] PyBench DictCreation (was Re: Performance compares) (original) (raw)

M.-A. Lemburg mal@lemburg.com
Fri, 18 May 2001 13:36:28 +0200

Tim Peters wrote:

[MAL] > FYI, I have a patch which inlines small dictionaries directly > into the type object You don't mean that, but how about uploading the patch to SF anyway? Assign it to me and I'll dig into it.

Right, I meant the dict object... (the "not enough coffee" thingie again ;-)

> ... > I've experimented with the minimal size a lot and found that > setting it to 8 slots gives the bext performance/memory tradeoff.

Having done just a couple rounds of instrumented runs across various apps, I was moving to that conclusion too. Also that "small" dicts are so common that avoiding the "extra" malloc would be a nice win for them, and that large dicts are rare enough and resizing expensive enough anyway that the new cost of doing a two-headed allocation strategy would be lost in the noise. IOW, I'm inclined to believe that everything you say your patch does is Good For Python, and Guido is so sympathetic to my lack of sleep lately that I bet he'll let me slip in one uglification without scowling .

I'll see if I find time today to rework the patch for Python CVS. The patch is hiding in my old Python 1.5 killer patch ;-) -- which gives more than a 50% boost on my machine, but that's another story.

-- Marc-Andre Lemburg CEO eGenix.com Software GmbH

Company & Consulting: http://www.egenix.com/ Python Software: http://www.lemburg.com/python/